Litter decomposition experiments
Referring to the methods described by Jiang et al. (2021), leaf-litter decomposition rates were measured using a laboratory microcosm experiment under standardised conditions (i.e. decomposability). A total of 60 microcosms (15 species × four replicates) were set up. Each microcosm was constructed using polyvinyl chloride pipe (10 cm in length and 8 cm in diameter) and homogenised fresh soil (100.002 ± 0.003 g) plus oven-dried leaf litter (2.000 ± 0.0002 g) per species. Leaf samples were placed on the soil surface and separated using a nylon net (7 × 7 cm, 1 mm mesh). These microcosms were incubated in the dark (25 ± 0.02 °C, 70 ± 5% humidity) throughout the experiment. They were watered with distilled water (once every two weeks) to maintain soil moisture at 60% of water-holding capacity throughout the incubation period. Each microcosm was covered with a perforated adherent film to reduce humidity loss while allowing gaseous exchange. After a 12-wk incubation, the microcosms were disturbed, and the residual leaf litter was carefully picked up using tweezers, oven-dried at 60 °C, and weighed to determine the mass loss (ML).